FIG. 7 shows one embodiment of a conventional illuminating device. (Patent Document 1)
This illuminating device 50 continually illuminates interiors of an ash tray 51 and a console box 53, characterized in that an illuminating lamp 56 is arranged at a position where the ash tray 51 being pulled out is prevented from blocking light path from the illuminating lamp 56.
The ash tray 51 is arranged over the console box 53 to be engaged slidably with an ash tray holder 52 having a front opening and a lower opening. A lamp case 55, in which an illuminating lamp 56 is embedded, is attached to an upper wall 52a of the ash tray holder 52, arranged at a right end and a center in a back and forth direction of the ash tray holder 52. Further, a lighting window 52b is formed on the upper wall 52a to pass the light of the illuminating lamp 56 therethrough.
The lamp case 55 is projected from the right side of the ash tray holder 52 upwardly, and the light from the illuminating lamp 56 illuminates downward an interior of the console box 53 through the lower opening of the lamp case 55. Further, a reflector 57 extending downward is formed on the projecting portion of the lamp case 55, so that the light from the illuminating lamp 56 is reflected by the reflector 57 to illuminate the interior of the console box 53 widely.
According to this structure, since the lamp case 55 is projected rightward from, and centered in the ash tray holder 52, even if the ash tray 51 is pulled out from the ash tray holder 52, the ash tray 51 can be illuminated, and the console box 53 can be illuminated simultaneously.
FIG. 8 shows a second embodiment of the conventional illumination device (Patent Document 2). This embodiment provides an illumination device 60 to illuminate an interior of a console box 66 suitably brightly at low power consumption, comprising a lamp body 61, a substrate 63 attached to the lamp body 61, and a lens 65 covering the substrate 63.
The lamp body 61 is made of synthetic resin in a box-like shape as a whole. An attaching part 62 to attach the illumination device 60 to a wall surface of the console box 66 is provided at a lower part of the lamp body 61. The substrate 63 and the lens 65 are respectively fixed on the lamp body 61 by fixing means.
A plurality of LED chips 64 are mounted on the substrate 63. The LED chips 64 are arranged in a line, namely, a light source has a line shape. Electronic parts, such as a rectifier diode for preventing noise and current limiting resistor, are also mounted on the substrate 63.
The lens 65 is made of optically transparent synthetic resin in a box-like shape. Therefore, the console box 66 is illuminated widely by light being emitted from the LED chips 64 and passing through the lens 65.
According to above structure, since many LED chips 64 are mounted, the interior of the glove compartment can be illuminated sufficiently brightly and the illumination device 60 with low power consumption can be provided.
FIG. 9 shows a third embodiment of the conventional illumination device. This embodiment, like first and second embodiments described above, provides an illumination device 70 having LED chips, and being attached to the small container such as the console box or the grove box. The illumination device 70 is connected to a wire harness 75 arranged in a vehicle, through a joint connector 71, a branch line 72, and a module connector 73 at a module side.
When installing an additional illumination device 70, the joint connector 71, the branch line 72, and the module connector 73 are newly prepared and arranged along the wire harness 75 in a same manner as other illumination devices 70.
However, these first to third embodiments have problems below. In the first embodiment, since the light of the illuminating lamp 56 is diffused light and its intensity is high, there is a problem that the light leaks to outside of the console box 53. Further, if the illuminating lamp 56 is an incandescent lamp, there is another problem that such a lump has a short life because of its high power consumption and high heating value.
The second embodiment comprises the LED chips 64 as a light source to solve the problem of the first embodiment, however, there is a problem below.
In this embodiment, since the LED chips 64 are mounted on the substrate 63, the lamp body 61 becomes large and cannot be attached to the small container having a small space. For example, the lamp body 61 cannot be attached to such as an ash tray or a cup holder. If narrowing gaps between the LED chips 64 for miniaturizing the illumination device 60, there is a problem that heat radiation efficiency of the illumination device 60 is reduced, a temperature of an inside of the illumination device 60 is increased, and luminous efficiency is reduced. Particularly luminous efficiency of a red LED chip falls rapidly with increasing temperature.
When the illumination device 60 is used for a small container such as an ash tray or a cup holder, since high illumination is not needed, a small number of the LED chips 64 is enough for the illumination device 60 to have, while when the illumination device 60 is used for a console box, a glove box or a map light, since high illumination is needed, the illumination device 60 needs to have a large number of the LED chips 64. Thus, the required number of the LED chips 64 differs according to a size of the small containers or a place to be illuminated. However, there is a problem that said illumination device 60 cannot flexibly adapt to an increase or a decrease in the number of the LED chips 64, so that the lamp body 61, the substrate 63, and the lens 65 should be reformed and a total cost, including a cost for metal molds, increases.
The third embodiment comprises the LED chips 64 as the light source like the second embodiment, however, there is a problem below.
In this embodiment, the illumination device 70 cannot be miniaturized, because the illumination device 70 is connected to the branch line 72. Further, since the illumination device 70 is connected to the wire harness 75 through the joint connector 71, the branch line 72, and the module connector 73, there is a problem that the number of the parts is large and a total cost increases. Further, it is troublesome and time-consuming to install an additional illumination device 70.
Heretofore, there is proposed for use in an interior illumination in a vehicle that a lamp module is formed by individual light emitters such as lamps (bulbs) or LEDs.
In this case, for example, when a plurality of light emitters are arranged in parallel for increasing intensity of the illumination, a lamp module assembly 150 is formed, as shown in FIG. 22, by providing a plurality of junction connectors 142 in series in the middle of a wire harness (trunk line) 141, branching branch harnesses 143 from the junction connectors 142, and at each branch harness 143, a connector 145 connecting a lamp module 144 to said branch harness 143.
Each lamp module 144 includes a case 146 made of synthetic resin, a light emitter 147 received by the case 146, and a lead terminal 148 connected to the light emitter 147. By connecting the lead terminal 148 to a female terminal (not shown) in the connector 145, the branch harnesses 143 and the light emitter 147 are connected together. When being a female terminal, the lead terminal 148 is connected to a male terminal in the connector 145.
When an LED (light emitting diode) is used for the light emitter 147, a resistor 149 is provided in the lamp module 144 for reducing voltage. The resistor 149 is electrically connected between the positive lead terminal and light emitter 147. FIG. 23 shows one embodiment of an equivalent circuit having the resistor 149 and the light emitter 147 in the lamp module 144.
For example, while a vehicle battery voltage is 12 volts, a rated voltage of an LED is 3.5 volts. Therefore, the battery voltage should be reduced to 3.5 volts. Apart from the resistor 49, a semiconductor element such as a diode is often provided for protecting the LED 147 from static electricity and the like.
In addition to the above described art, for example, Patent Document 3 discloses a structure, in which a plurality of chip type LEDs as light emitters are arranged in parallel in one lamp module.
Since the LED consumes low electric power, and has a small size, the LED allows to be used for a continuous illumination, and allows the lamp module to be miniaturized.
However, it is preferable that the number of the light emitters is set properly according to a place in which the lamp module is used, and according to required intensity. From this point of view, the later lamp module having a plurality of light emitters as described in Patent Document 3 is inadequate.
However, there is a problem that, for arranging the suitable number of the lamp modules shown in FIG. 22 with branch wires, each of which having one light emitter, many parts such as junction connectors 142, branch harnesses 143 and the connectors 145 are required. Further, the lamp module assembly requires a complex, upsized and high-cost structure. Further, many man-hours are required to assemble and connect the lamp module assembly.
Patent Document 4 discloses a structure for arranging a plurality of LEDs connected to two electric wires without any branch wires, wherein an LED chip is molded into a plastic bulb, and connected respectively to two lead parts with bonding wires. Then, pressure contact terminals continued integrally to the lead parts are pressed into contact with the electric wires in a lamp holder made of synthetic resin.
However, in the LED lamp module described in Patent Document 4, since it is necessary to connect the LED chip to respective lead terminals with thin bonding wires, workers should pay close attention to said bonding. Further, an assembly operation of said LED lamp module requires a lot of man-hours and a severe quality control. Further, after being inserted into the holder, the pressure contact terminal is pressed into contact with the electric wire. Therefore, its workability may be low when the numbers of the pressure contact terminals to be in contact with electric wires is large.
Further, as a Lamp module assembly 150 shown in FIG. 22, when the resistor 149 is arranged in a case of each LED lamp module 144, said LED lamp module becomes large. Further, the number of the components of resistors 149 is increased to increase components cost. Further, the Lamp module assembly 150 becomes large to need a larger space to be mounted in a vehicle. Further, a production cost of the Lamp module assembly 50 becomes higher.
[Patent Document 1]
Japanese Utility Model Application Laid-Open No. Hei 6-1476 (Page 2, FIG. 1)
[Patent Document 1]
Japanese Utility Model Application Laid-Open No. Hei 9-272377 (Pages 2 to 4, FIG. 1)
[Patent Document 3]
Japanese Patent Application Laid-Open No. Hei 09-272377 (Pages 3 to 4, FIGS. 1 and 5)
[Patent Document 4]
Japanese Patent Application Laid-Open No. Hei 11-121807 (Pages 4 to 5, FIGS. 1 to 3)